The Yemeni civil aviation authority announced on 19 September that flights to Sanaa International Airport would be suspended for 24 hours due to Houthi armed activity in the vicinity.
Flights were diverted to Aden airport. The state-news agency, Saba, reported that mortar fire had targeted the headquarters of the state television channel while Houthi gunmen fought with security forces in the vicinity of the building on 18 September. Fighting between pro-Houthi gunmen and supporters of the Islamist Islah political party backed by security forces is still on-going in Shamlan on the northern outskirts of the capital, and the nearby Salafist Iman University in Sofan, 8.5 kilometres southwest of Sanaa International Airport.
A large contingent of Houthi fighters currently fighting Islah and government forces are drawn from northern tribes opposed to Islah and Saudi-backed Salafists, rather than being members of the core Houthi 'Al-Shabaab al-Moumineen' fighters. Houthi fighters also took control of security checkpoints on the Sanaa-Amran road, 5 km west of the airport. Unconfirmed social media reports maintained that Houthi fighters have set-up checkpoints along '60-metre' road in the west of Sanaa, and that there was fighting in the vicinity of the Ministry of Information. Moreover, thousands of Houthi protesters are planning protests along the airport access road, while gunmen attacked a military checkpoint near the airport.
Meanwhile, the meeting between the Special Advisor to the United Nations' Secretary-General, Jamal Benomar, and Houthi leader Abdul-Malak al-Houthi on 18 September in Sa'da province ended without an agreement. Saudi newspaper Al-Sharq al-Awsat reported that Omani and Iranian mediation is attempting to reach a settlement with the Houthi. The US ambassador to Yemen in a press conference re-iterated support for Yemeni President Abdurabu Mansour Hadi, and maintained that the United States along with G10 colleagues are prepared to take action against individuals threatening Yemen's political transition, probably referring to United Nations Security Council Resolution 2140.
The proximity of fighting to Sanaa airport and suspension of civilian flights presents a severe risk of the airport and adjacent military airbase coming under indirect fire, with a high risk of armed protesters attempting to overrun both. However, attacks on civil aviation and incurring mass civilian Yemeni casualties would jeopardise the Houthi support base on which their southward advance towards Sanaa has been contingent, somewhat mitigating the risk. Fighting is likely to intensify in the north and western parts of Sanaa and spread to central parts, presenting severe risks of collateral damage to property, particularly around government buildings and religious institutions. In the increasingly likely event that mediation fails and fighting intensifies in the capital, there is a high risk of Hadi being forced to temporarily relocate the government from Sanaa. In this scenario, the ability of the government to restore control over the north would be extremely low. Simultaneously, the ability of Hadi to control the south would be equally low. This would in essence be a combination of de facto partition resulting from state collapse.